Wing Flashing’s

Time: 8 Hours

The wings have two Flashing’s, forward and aft, that cover up the open space between the wings and fuselage. They will be held onto the wings with screws and have a rubber seal on the edge the meets up with the fuselage to make a tight seal. The aft one isn’t too bad after you remove enough material so that you can access the holes in the wing through the holes in the flashing. I removed just enough of the inboard edge to get the flashing to fit without touching the fuselage. The forward flashing was a little more work as you have to bend it around the wing to get it to fit nice and tight. Once you get that fit just right you match for all the holes that are in the flashing through undrilled skin of the fuel tank flange.  

   With The flashings in place I used my compass with a fine tipped blue sharpie to draw a line 3/16″ away from the fuselage onto the flashing’s. I will remove this material to allow for the rubber seal that will get placed on there later. 
   Before I moved onto the left-wing I wanted to finish up the instrument panel not plates as they were sitting on my bench taking up space.  
 Now I just need to paint this its final color and I can screw it into position. Now I just need the avionics to add to the panel! I moved on to the left wings flashing’s repeating the steps I did on the right wing.  

 From here I removed both sides and trimmed up to the 3/16″ line I made to make room for the gap seal. I then reinstalled the flashing’s so that I could work on the flap fairing’s. You have to manipulate these a little to get a good fit with the top of the flap and the curved portion of the fuselage. Once I had a good fit with the right one I taped/clamped it into position so that I could match drill the forward top holes through the fuselage into this fairing.  

 I drilled each end and then worked down the line.   

  Once I had that line done I worked my way aft on the top and bottom making sure everything was fitting tight.  

 I repeated these steps on the left side and was pretty happy with the results.  

   That’s where I stopped for the day, good progress and feels good to have the major work done on these flashing’s and fairing’s. I still need to fine tune the areas where the flashing’s and fairing’s meet. Then I will clean up all the edges and enlarge the holes to a #19 for #8 screws that will hold them in place when I’m done. Looks more like an RV-8 every day! 


Gear Bolt Mod

Time: 5 Hours

If you remember in my previous blog posts I did quite a bit of work to the landing gear towers to open them up and make it easier, relatively speaking, to access the landing gear bolt nuts. The boats go up through landing gear into the landing gear tower where the nuts needed to be torqued. This task has proved to be very difficult for many builders as there’s not a whole lot of room in the towers. Not too long ago my buddy Glenn and I read about another builder and some clips he was making and selling. These look very cool to us and thought we would try them! What they are is a couple pieces of strong steal U-channel that is just wide enough that the head of the gear bolt, when turned correctly, fit in between. A hole is drilled to allow the bolt to slide down through and the head be sandwiched between the two flanges of the U shape. Here are a couple photos to better describe what I’m talking about. 

   The theory here is that the bolts would be installed backwards or down through the gear towers and the gear legs versus up through them. This metal clip would then bind against another nut in the tower to prevent it from spinning. What this allows is the nut to be placed on the bottom of the gear legs, easily accessible to torque with just one person as the bolt head would remain stationary due to these clips. 
   After five hours of swearing, removing various nuts, holding back wires that are run and moving brake lines I was able to modify and manipulate these clips along with the bolts to finally get them in their final position! The clips needed some modifications to fit around other nuts that are in the gear tower as the tolerances are pretty close in the space. So you read that correctly five hours to install four bolts! The first picture shows you the normal condition with the nut inside the gear tower and how hard it would be to get a socket and torque wrench in there to adjust these. The second photo shows the mod with the bolts going down through.
   I did buy new gear bolts to adjust for the slight increase in thickness of the clips as well as to address the original bolts that were only showing one maybe one and a half threads. I ordered new bolts from Genuine Aircraft Hardware and adjusted the bolt I ordered. The original bolt was a close tolerance NAS6206-27 bolt. I ordered a NAS6606-27 bolt to replace it. This new bolt has the same grip length just a little longer threaded portion which adds to the overall length of the bolt by about 1/8″. Now I have 2 to 3 threads showing outside of the nut as it is torqued. As for was this modification worth it in the pain in the butt it it was to get these bolts and clips down in the tower? A definitely yes as it took me 10 seconds to torque the nut and I could do it all by myself. These bolts and nuts will need to be torqued every one hundred flight hours and this mod allows me to do that by myself very easily. So a little hardship now will pay off greatly in the long term, I only wish that I had done this mod back when I was assembling the landing gear which would’ve made it so much easier!

Aileron and Flap Rigging

Time: 8 Hours

This weekends task was to finish up the fuel connection lines from the fuselage to the wing tanks and rig both the ailerons and flaps. The fuel lines consist of a connection for the vent line and a connection for the fuel feed. Since I had used flop tubes, for inverted flight, I had a little bit different fuel feed line vs the standard pick ups. The lines have to travel through the hole that was drilled in the tank attach brackets. They will also have a union in the line where the standard ones don’t. The vent lines just have to clear the brackets staying below the skin level so they will be hidden under the flashing that will get put there. I made the lines and their connections minus the end that goes on the fuel line that comes out of the fuselage. That will get cut and flared after the wings are removed to make room.  

   Once I had the fuel lines done I moved on to the big task of rigging the ailerons and flaps. First up is to attach the ailerons to the wings and set the neutral point. I used a digital level which has a magnet and stuck it to my control stick to get perfect neutral stick. 

 With the stick in neutral I adjusted both of the ailerons so that they were in their neutral position. This is done by aligning three tooling holes in the outboard rib and the aileron tip. When all three line up the aileron is in neutral position.  

  Once I had both ailerons on and adjusted to be in the neutral position I had to make adjustments back at the control stick to return it to the neutral position. This is done by adjusting the rod ends on the two pushrods the connect to the control stick.  Once the ailerons have been adjusted you can move on to the flaps to line them up.  Before doing this I put in the aileron judgment tool the Vans gives you to hold neutral position. This is a jig that has a hole in it for the aileron rod bolt to go through and a flat surface to sit against the wing spar. When installed the bell crank is in its neutral position but also holds the ailerons from moving.  With the jig in place I know that ailerons will not move and I can adjust the flaps to match them. The flaps need to line up with the ailerons so that as you look down the wing in neutral position the ailerons and flaps trailing edge is lined up in a perfect line. To do this with the flaps you just adjust the pushrod either up or down to get the flaps to line up with the ailerons. Before you can do this you need to enlarge the hole in which the pushrod it goes up-and-down through.  
   You need to open this whole up as when the pushrod goes up-and-down it’s geometry changes moving the pushrod forward and aft as it moves. Once you have this whole opened in the pushrod no longer hits the skin you just adjust its length to align the flaps trailing edge with the ailerons in there up position.  
 With the flaps adjusted both left and right I removed the aileron jig to check their travel in the up and down position and compare to the degrees that vans specifies.   
 All the measurements were dead on and perfect!  One thing I did find with my flaps was that I did not bend the rears are flange enough when I built the wings. This caused the wings skin to curl up just a little at the aft end of the top skin. Vans knows that this is an issue for builders and describes how to correct this with a 2 x 4 jig. I took a 2 x 4 and cut a slot in it and drilled out the center in order to bend the flange without bending the skin as I do that. 

 The idea is that the slot would allow the 2 x 4 to slide over the skin at the very tip I opened up the slot a little to slide over the rivet heads on the rear spar flange then I could use the 2 x 4 to slowly bend the flange down in turn lowering the skin. 

   This worked out well and I will do a little more tweaking on it to get it perfect. What is fun is that I can make the flaps go up and down using a 9 V battery with it’s flat motor. Kind of fun to see things working like they should!